Months after divorcing the world’s richest man, MacKenzie Bezos has pledged to give at least half of her estimated $36.6 billion fortune to charity. MacKenzie became one of the richest people in the world after finalizing her divorce from Amazon’s founder, Jeff Bezos, and now ranks 22nd on the Bloomberg Billionaires Index. “I have a disproportionate amount of money to share,” Bezos said in a letter announcing her pledge. “My approach to philanthropy will continue to be thoughtful. It will take time and effort and care. But I won’t wait. And I will keep at it until the safe is empty,” Bezos said. Her ex-husband, himself worth roughly $114 billion, praised his ex-wife’s decision. “MacKenzie is going to be amazing and thoughtful and effective at philanthropy, and I’m proud of her,” the CEO tweeted.

MacKenzie’s decision is part of the Giving Pledge, an initiative that encourages the world’s richest people to donate a majority of their wealth to charitable causes. The pledge was started by Warren Buffett and Bill and Melinda Gates in 2010, and has so far attracted the support of 204 individuals and families.